2003 MERCEDES-BENZ G55AMG check engine light

243 Practical hints
What to do if …
Problem
Possible cause
Suggested solution
?
The yellow “CHECK ENGINE”
malfunction indicator lamp
comes on while driving.
There is a malfunction of:

The fuel management system


The ignition system


The emission control system


Systems which impact emissions
Such malfunctions may result in excessive
emissions values and may switch the engine
to its limp-home (emergency operation)
mode. Serious damage can occur to the
emission system.

Have the vehicle checked as soon as
possible by an authorized
Mercedes-Benz Light Truck Center.
An on-board diagnostic connector is
used by the service station to link the
vehicle to the shop diagnostics sys-
tem. It allows the accurate identifica-
tion of system malfunctions through
the readout of diagnostic trouble
c o d e s . I t i s l o c a t e d n e a r t h e h o o d l o c k
release on the upper left of footwell.
The fuel cap is not closed tightly.

Check the fuel cap.
Your gas tank is empty.

After refuelling, start the engine three
or four times in succession. The
limp-home mode is canceled.
<
The red seat belt warning lamp
blinks for a brief period after
starting the engine.
The warning lamp reminds you to fasten seat
belts.

Fasten your seat belt.
The yellow fuel tank reserve warning lamp
illuminates while driving.
The fuel level has gone below the reserve
mark.

Refuel at the next gas station.

Also note the messages in the multi-
function display (
page 246).

249 Practical hints
What to do if …
Display
Possible cause
Suggested solution
Category
#
BATTERY/ALTERNATOR
VISIT WORKSHOP!
The battery was charged with a bat-
tery charger or jump started.

Have the battery checked at a
service station.
2
The battery is no longer charging.
Possible causes:

alternator malfunctioning


broken poly-V-belt

Stop immediately and check
the poly-V-belt.
If it is broken:

Do not continue to drive. Oth-
erwise the engine will overheat
due to an inoperative water
pump which may result in seri-
ous engine damage not cov-
ered by the Mercedes-Benz
Limited Warranty. Notify an
authorized Mercedes-Benz
Light Truck Center.
If it is intact:

Turn off unnecessary electric
consumers.

Drive immediately to the near-
est authorized Mercedes-Benz
Light Truck Center.

250 Practical hintsWhat to do if …Display
Possible cause
Suggested solution
Category
3
(Canada only)
;
(USA only)
BRAKE PAD WEAR
VISIT WORKSHOP!
The brake pads have reached their
wear limit.

Have the brake pads replaced
as soon as possible.
2
BRAKE FLUID
VISIT WORKSHOP!
There is insufficient brake fluid in the
reservoir.

Risk of accident! Stop the vehi-
cle and notify an authorized
Mercedes-Benz Light Truck
Center. Do not add brake fluid!
This will not solve the problem.
2
Warning!
G
Driving with the last message displayed can
result in an accident. Have your brake sys-
tem checked immediately.
Don’t add brake fluid before checking the
brake system. Overfilling the brake fluid res-
ervoir can result in spilling brake fluid on hot
engine parts and the brake fluid catching
fire. You can be seriously burned.
!If you find that the brake fluid in the
brake fluid reservoir has fallen to the
minimum mark or below, have the
brake system checked for brake pad
thickness and leaks. !Brake pad thickness must be visually
checked by a qualified technician at the
intervals specified in the Service book-
let.

251 Practical hints
What to do if …
Display
Possible cause
Suggested solution
Category
B
COOLANT
CHECK LEVEL!
The coolant level is too low.

Add coolant (
page 220).

If you have to add coolant fre-
quently, have the cooling sys-
tem checked by an authorized
Mercedes-Benz Light Truck
Center.
2
Warning!
G
Do not spill antifreeze on hot engine parts.
Antifreeze contains ethylene glycol which
may burn if it comes into contact with hot
engine parts. You can be seriously burned.
!Do not ignore the low engine coolant
level warning. Extended driving with
the message and symbol displayed
may cause serious engine damage not
covered by the Mercedes-Benz Limited
Warranty.
Do not drive without sufficient amount
of coolant in the cooling system. The
engine will overheat causing serious
engine damage.
Observe the coolant temperature dis-
play (
page 108).

253 Practical hints
What to do if …
Display
Possible cause
Suggested solution
Category
B
COOLANT
STOP, ENGINE OFF!
The poly-V-belt could be broken.

Stop immediately and check
the poly-V-belt.
If it is broken:

Do not continue to drive. Oth-
erwise the engine will overheat
due to an inoperative water
pump which may result in
damage to the engine. Notify
an authorized Mercedes-Benz
Light Truck Center.
If it is in order:

Do not continue to drive the
vehicle with this message dis-
played. Doing so could result
in serious engine damage that
is not covered by the
Mercedes-Benz Limited War-
ranty.
1
COOLANT
VISIT WORKSHOP!
The cooling fan for the coolant is
malfunctioning.

Observe the coolant tempera-
ture display (
page 108).

Have the fan replaced as soon
as possible.
2

254 Practical hintsWhat to do if …Display
Possible cause
Suggested solution
Category
Ñ
CRUISE CONTROL
VISIT WORKSHOP!
Cruise control is malfunctioning.

Visit an authorized
Mercedes-Benz Light Truck
Center.
2
J
DOOR OPEN!
You are attempting to drive with one
or more doors open.

Close the doors.
1
e
ENGINE AIR FILTER
VISIT WORKSHOP!
The engine filter is clogged and must
be replaced.

Visit an authorized
Mercedes-Benz Light Truck
Center as soon as possible.
2
:
ENGINE OIL LEVEL
STOP, ENGINE OFF!
There is no oil in the engine. There is
a danger of engine damage.
See also comments on the following
page.

Carefully bring the vehicle to a
halt as soon as possible.

Turn off the engine.

Add engine oil and check the
engine oil level (
page 218).
1
ENGINE OIL LEVEL
CHECK LEVEL!
The engine oil level is too low.
See also comments on the following
page.

Check the engine oil level
(page 218) and add oil as re-
quired.
2
ENGINE OIL LEVEL
REDUCE OIL LEVEL!
You have added too much engine oil.
There is a risk of damaging the en-
gine or the catalytic converter.
See also comments on the following
page.

Have oil siphoned. Observe all
legal requirements with re-
spect to its disposal.
2

255 Practical hints
What to do if …
When the ENGINE OIL LEVEL – CHECK
LEVEL! message appears while the engine
is running and at operating temperature,
the engine oil level has dropped to approx-
imately the minimum mark on the dipstick.
When this occurs, the warning will first
come on intermittently and then stay on if
the oil level drops further.If no oil leaks are noted, continue to drive
to the nearest service station where the
engine oil should be topped to the “full”
mark on the dipstick with an approved oil.:
ENGINE OIL
VISIT WORKSHOP!
The engine oil has dropped to a crit-
ical level.

Check the engine oil level
(page 218) and add oil as re-
quired.

If you must add engine oil fre-
quently, have the engine
checked for possible leaks.
2
There is water in the oil.

Have the oil checked.
ENGINE OIL LEVEL
VISIT WORKSHOP!
The measuring system is malfunc-
tioning.

Have the measuring system
checked by an authorized
Mercedes-Benz Light Truck
Center.
2
Display
Possible cause
Suggested solution
Category
!The engine oil level warnings should
not be ignored. Extended driving with
the symbol displayed could result in se-
rious engine damage that is not cov-
ered by the Mercedes-Benz Limited
Warranty.

257 Practical hints
What to do if …
ESP
ELEC. STABIL. PROG.
NOT AVAILABLE
The ESP is deactivated because of a
malfunction or interrupted power
supply. The ABS might not be opera-
tional.
The system must be resynchronized.

With vehicle stationary and the
engine running, turn the steer-
ing wheel completely to the
left and then to the right to
synchronize the ESP.
If the ESP message does not go
out:

Continue driving with added
caution.

Visit an authorized
Mercedes-Benz Light Truck
Center as soon as possible.
Failure to follow these instructions
increases the risk of accident.
2
The ESP is temporarily unavailable.
The self-diagnosis has not been
completed.
The display will clear itself after
driving a short distance at more
than 12 mph (20 km/h).
The charging voltage has fallen be-
low 10 volts and the ESP has
switched off.

When the voltage is above this
value again, the ESP is opera-
tional again.

If necessary, have the genera-
tor and battery checked.
2
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